title: Rubrenes: planar and twisted.
abstract: Surprisingly, despite its very high mobility in a single crystal, rubrene shows very low mobility in vacuum-sublimed or solution-processed organic thin-film transistors. We synthesized several rubrene analogues with electron-withdrawing and electron-donating substituents and found that most of the substituted rubrenes are not planar in the solid state. Moreover, we conclude (based on experimental and calculated data) that even parent rubrene is not planar in solution and in thin films. This discovery explains why high mobility is reported in rubrene single crystals, but rubrene shows very low field-effect mobility in thin films. The substituted rubrenes obtained in this work have significantly better solubility than parent rubrene and some even form films and not crystals after evaporation of the solvent. Thus, substituted rubrenes are promising materials for organic light-emitting diode (OLED) applications.
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Abhimanyu S
authors.initials: AS
authors.lastname: Paraskar
authors.forename: A Ravikumar
authors.initials: AR
authors.lastname: Reddy
authors.forename: Asit
authors.initials: A
authors.lastname: Patra
authors.forename: Yair H
authors.initials: YH
authors.lastname: Wijsboom
authors.forename: Ori
authors.initials: O
authors.lastname: Gidron
authors.forename: Linda J W
authors.initials: LJ
authors.lastname: Shimon
authors.forename: Gregory
authors.initials: G
authors.lastname: Leitus
authors.forename: Michael
authors.initials: M
authors.lastname: Bendikov